/*
day269
2020.5.23
*/
#include<vector>
#include<algorithm>
#include<stack>
#include<iostream> 
using namespace std;

struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

class Solution {
public:
    TreeNode* trimBST(TreeNode* root, int L, int R) {
    	if(!root)
		{
			return nullptr;
		 } 
        if(root->val>R)
        {
        	return trimBST(root->left,L,R);
		}
		if(root->val<L)
        {
        	return trimBST(root->right,L,R);
		}
		
		root->left=trimBST(root->left,L,R);
		root->right=trimBST(root->right,L,R);
		
		return root;
    }
};



int main()
{
	return 0;
 } 
